CN-116730274-B - Mounting structure of micro vibrator

CN116730274BCN 116730274 BCN116730274 BCN 116730274BCN-116730274-B

Abstract

In the mounting structure, the micro vibrator (2) has a curved surface portion (21) having a hemispherical curved surface, a connection portion (22) extending from the curved surface portion toward a hemispherical center of the curved surface portion, and a surface electrode (23) covering at least a part of the connection portion and at least a part of the curved surface portion. The mounting substrate (3) has two or more wirings (42), and a part of the micro vibrator is connected to the mounting substrate. The wirings each have an electrode connection portion (421), and the electrode connection portion (421) is connected to a portion of the surface electrode covering the connection portion at the end. The two or more wirings include a voltage application wiring (42A) for applying a voltage to the surface electrode and a voltage detection wiring (42B) for detecting the voltage applied to the surface electrode. The voltage applying wiring is spaced apart from the voltage detecting wiring on the mounting substrate.

Inventors

HARADA SHOTA
ITO KOTARO
NISHIKAWA HIDEAKI
INAGAKI KANJI
SAITO YOSHIAKI
YOSHIDA YOSHIHIKO
YUSUKE KAWAI

Assignees

株式会社电装
丰田自动车株式会社
未来瞻科技株式会社

Dates

Publication Date: 20260512
Application Date: 20230306
Priority Date: 20220308

Claims (5)

1. A mounting structure, comprising: A micro vibrator having a curved surface portion with a hemispherical curved surface, a connection portion extending from the curved surface portion toward a hemispherical center of the curved surface portion, and a surface electrode covering the connection portion at least at a portion and the curved surface portion at least at a portion, and A mounting substrate having two or more wirings, and a part of the micro vibrator being connected to the mounting substrate, wherein Each of the two or more wirings has an electrode connection portion connected at one end to a portion of the surface electrode covering the connection portion, The two or more wirings include a voltage applying wiring that applies a voltage to the surface electrode and a voltage detecting wiring that detects a voltage applied to the surface electrode, and The voltage applying wiring is spaced apart from the voltage detecting wiring on the mounting substrate.
2. The mounting structure of claim 1, wherein The mounting substrate is formed with a separation groove to separate the voltage detection wiring and the voltage application wiring from each other.
3. The mounting structure of claim 1 or 2, wherein The surface electrode includes a plurality of branch electrodes, the number of which is the same as the electrode connection portions of the two or more wirings, The plurality of branch electrodes are disposed at positions covering the sidewall surfaces of the connection portions and corresponding to the electrode connection portions, The side wall surface of the connecting portion is exposed from the surface electrode at a position between the plurality of branch electrodes, and Each of the electrode connection portions is connected to a different one of the plurality of branch electrodes through a coupling member.
4. The mounting structure of claim 1 or 2, wherein The micro vibrator has a bottom protrusion on a mounting surface defined at a bottom of the connection portion, and The mounting substrate has a facing region facing the connection portion of the micro vibrator, and The mounting substrate is formed with a fitting recess to receive the bottom protrusion of the connection portion therein in the facing region.
5. The mounting structure of claim 1 or 2, wherein The electrode connection portions of the two or more wirings are in contact with and directly bonded to the surface electrode portion.

Description

Mounting structure of micro vibrator Technical Field The present disclosure relates to a mounting structure of a micro vibrator having a three-dimensional curved surface. Background A system for automatic driving of a vehicle has been developed in recent years. Such a system requires a technique for estimating its position with high accuracy. For example, self-position estimation systems equipped with Global Navigation Satellite Systems (GNSS) and Internal Measurement Units (IMU) for so-called three-level autopilot have been developed. The IMU is, for example, a six-axis inertial sensor composed of a three-axis gyro sensor and a three-axis acceleration sensor. In the future, in order to achieve four or more level automatic driving, IMUs having higher sensitivity than the current systems are required. To achieve such high sensitivity IMUs, bird-Bowl Resonator Gyroscopes (BRGs) are considered promising gyroscopic sensors. The BRG has a mounting substrate and a micro vibrator mounted on the mounting substrate. The microvibrators have a substantially hemispherical three-dimensional curved surface and vibrate in a wineglass mode. The micro-vibrator has a Q factor of 10 6 or more, which represents a vibration state. Thus, it is desirable that the micro-vibrator achieve higher sensitivity than the previous micro-vibrator. For example, US2019/0094024A1 discloses a mounting structure of a microvibrator of this type on a mounting substrate. In the disclosed mounting structure, the microvibrator has a substantially hemispherical three-dimensional curved surface and a joining portion extending from near the top of the hemispherical three-dimensional shape toward the center of the hemispherical shape. The bonding portion is shaped as a bottomed tube and defines a recess recessed from the top of the hemispherical three-dimensional shape of the curved surface. The bonding portion is inserted into a bonding region of the mounting substrate surrounded by the substantially annular frame. In this mounting structure, the surface electrode covering the entire surface of the micro vibrator and the wiring formed in the bonding region of the mounting substrate are bonded to each other, so that a predetermined voltage can be applied to the surface electrode of the micro vibrator via the wiring of the mounting substrate. Disclosure of Invention In the disclosed BRG, the micro-vibrator is bonded to a bonding region on the mounting substrate that is electrically connected to the wiring, so that a voltage is applied to the surface electrode of the micro-vibrator via the wiring on the mounting substrate. Therefore, in order to secure stability of voltage application, bonding reliability between the micro vibrator and the mounting substrate is important. Further, in this mounting structure, in order to confirm whether or not a voltage is applied to the surface electrode of the micro vibrator, it is necessary to detect the voltage by connecting a probe to a portion of the surface electrode other than the bonded portion with the mounting substrate. However, if the probe is in direct contact with the surface electrode of the micro-vibrator, the surface electrode or the substrate covered with the surface electrode may be damaged, and if the surface electrode or the substrate is damaged, the Q factor of the micro-vibrator may be lowered, and furthermore, for example, when the cover is attached to the mounting substrate and the micro-vibrator is closed, the probe cannot be in contact with the surface electrode of the micro-vibrator, and thus the voltage applied to the surface electrode cannot be detected. An object of the present disclosure is to provide a mounting structure of a micro vibrator on a mounting substrate, the micro vibrator having a three-dimensional curved shape and including a surface electrode covering a surface thereof, which is capable of detecting an applied voltage to the surface electrode without contacting a portion of the surface electrode other than a bonding portion with the mounting substrate. According to one aspect of the present disclosure, a mounting structure includes a micro vibrator and a mounting substrate. The micro vibrator has a curved surface portion having a hemispherical curved surface, a connection portion extending from the curved surface portion toward a hemispherical center of the curved surface portion, and a surface electrode at least partially covering the connection portion and at least partially covering the curved surface portion. The mounting substrate has two or more wirings, and a portion of the micro vibrator is connected to the mounting substrate. The two or more wirings each have an electrode connection portion connected to a portion of the surface electrode covering the connection portion at the end. The two or more wirings include a voltage application wiring for applying a voltage to the surface electrode and a voltage detection wiring for detecting the voltage applied to the surface